var mongoose=require('mongoose');
var Post=mongoose.model('Post',{
    title:String,
    author:String,
    comments:[{
        content:String,
        like:{
            type:Number,
            default:0
        }
    }]
});
mongoose.connect('mongodb://localhost/MongoDB_QuanWei_2');


Post.remove({title:'post 1'},(err,r)=>{
    console.log(err,r);
});